Intravascular lithotripsy device that generates an advancing energy wavefront

Abstract

A catheter system ( 100 ) for treating a treatment site ( 106 ) includes a catheter shaft ( 110 ), a balloon ( 104 ), an energy source ( 124 ), a plurality of energy guides ( 122 A), and a system controller ( 126 ). The energy source ( 124 ) generates pulses of energy. The energy guides ( 122 A) are each configured to selectively receive at least one of the pulses of energy. Each of the energy guides ( 122 A) includes a guide distal end ( 122 D) that is positioned within a balloon interior ( 146 ) at a different longitudinal position from one another along a length ( 142 ) of the balloon ( 104 ). The system controller ( 126 ) ( i ) controls at least one of a pulse frequency, a pulse energy level and a pulse width of each of the pulses of energy, and (ii) controls a firing sequence of the pulses of energy such that the pulses of energy are sequentially directed to each of the energy guides ( 122 A), so that an advancing wavefront ( 835 ) is generated within the balloon interior ( 146 ) that moves toward the treatment site ( 106 ).

What is claimed is: 
     
         1 . A catheter system for treating a treatment site within or adjacent to a vessel wall of a blood vessel, the catheter system comprising:
 a catheter shaft;   a balloon that is coupled to the catheter shaft, the balloon includes a balloon first end, a balloon second end, and a balloon wall that defines a balloon interior, the balloon wall being configured to be positioned adjacent to the treatment site;   an energy source that generates a plurality of pulses of energy;   a plurality of energy guides that are each configured to selectively receive at least one of the plurality of pulses of energy from the energy source, each of the plurality of energy guides being disposed along the catheter shaft and at least partially within the balloon interior, the plurality of energy guides each including a corresponding guide distal end, each of the guide distal ends being positioned within the balloon interior at a different longitudinal position from one another along a length of the balloon; and   a system controller that (i) controls at least one of a pulse frequency, a pulse energy level and a pulse width of each of the plurality of pulses of energy from the energy source, and (ii) controls a firing sequence of the plurality of pulses of energy from the energy source such that the plurality of pulses of energy from the energy source are sequentially directed to each of the plurality of energy guides, so that an advancing wavefront is generated within the balloon interior that moves toward the treatment site in a first direction from near the balloon first end toward the balloon second end.   
     
     
         2 . The catheter system of  claim 1  wherein the system controller controls at least two of the pulse frequency, the pulse energy level and the pulse width of each of the plurality of pulses of energy from the energy source, so that the advancing wavefront is generated within the balloon interior that moves toward the treatment site in the first direction from near the balloon first end toward the balloon second end. 
     
     
         3 . The catheter system of  claim 2  wherein the system controller controls each of the pulse frequency, the pulse energy level and the pulse width of each of the plurality of pulses of energy from the energy source, so that the advancing wavefront is generated within the balloon interior that moves toward the treatment site in the first direction from near the balloon first end toward the balloon second end. 
     
     
         4 . The catheter system of  claim 1  wherein the system controller controls the pulse frequency so that the pulse frequency is increasing during the firing sequence of the plurality of pulses of energy from the energy source. 
     
     
         5 . The catheter system of  claim 1  wherein the system controller controls the pulse frequency so that the pulse frequency is decreasing during the firing sequence of the plurality of pulses of energy from the energy source. 
     
     
         6 . The catheter system of  claim 1  wherein the system controller controls the pulse energy level so that the pulse energy level is increasing during the firing sequence of the plurality of pulses of energy from the energy source. 
     
     
         7 . The catheter system of  claim 1  wherein the system controller controls the pulse energy level so that the pulse energy level is decreasing during the firing sequence of the plurality of pulses of energy from the energy source. 
     
     
         8 . The catheter system of  claim 1  wherein the system controller controls the energy source so that the pulse frequency is increasing and the pulse energy level of each of the plurality of pulses of energy is increasing during the firing sequence, so that the advancing wavefront is generated within the balloon interior that moves toward the treatment site in the first direction from near the balloon first end toward the balloon second end. 
     
     
         9 . The catheter system of  claim 1  wherein the system controller controls the energy source so that the pulse frequency is increasing and the pulse energy level of each of the plurality of pulses of energy is decreasing during the firing sequence, so that the advancing wavefront is generated within the balloon interior that moves toward the treatment site in the first direction from near the balloon first end toward the balloon second end. 
     
     
         10 . The catheter system of  claim 1  wherein the system controller controls the energy source so that the pulse frequency is decreasing and the pulse energy level of each of the plurality of pulses of energy is increasing during the firing sequence, so that the advancing wavefront is generated within the balloon interior that moves toward the treatment site in the first direction from near the balloon first end toward the balloon second end. 
     
     
         11 . The catheter system of  claim 1  wherein the system controller controls the energy source so that the pulse frequency is decreasing and the pulse energy level of each of the plurality of pulses of energy is decreasing during the firing sequence, so that the advancing wavefront is generated within the balloon interior that moves toward the treatment site in the first direction from near the balloon first end toward the balloon second end. 
     
     
         12 . The catheter system of  claim 1  further comprising a multiplexer that receives the plurality of pulses of energy from the energy source; and wherein the system controller controls the multiplexer such that the plurality of pulses of energy from the energy source are sequentially directed to each of the plurality of energy guides in accordance with the firing sequence. 
     
     
         13 . The catheter system of  claim 1  wherein the plurality of energy guides includes a first energy guide, a second energy guide and a third energy guide that are each disposed along the catheter shaft and at least partially within the balloon interior, (i) the first energy guide including a first guide distal end that is positioned within the balloon interior at a first longitudinal position along the length of the balloon, (ii) the second energy guide including a second guide distal end that is positioned within the balloon interior at a second longitudinal position along the length of the balloon that is different than the first longitudinal position, and (iii) the third energy guide including a third guide distal end that is positioned within the balloon interior at a third longitudinal position along the length of the balloon that is different than the first longitudinal position and the second longitudinal position, the second longitudinal position being between the first longitudinal position and the third longitudinal position along the length of the balloon; and wherein the system controller controls the energy source such that that the plurality of pulses of energy from the energy source are sequentially directed to the first energy guide, then the second energy guide, and then the third energy guide so that the advancing wavefront is generated within the balloon interior that moves toward the treatment site in the first direction from near the balloon first end toward the balloon second end. 
     
     
         14 . The catheter system of  claim 13  wherein the plurality of energy guides further includes a fourth energy guide that is disposed along the catheter shaft and at least partially within the balloon interior, the fourth energy guide including a fourth guide distal end that is positioned within the balloon interior at a fourth longitudinal position along the length of the balloon that is different than the first longitudinal position, the second longitudinal position and the third longitudinal position, the third longitudinal position being between the second longitudinal position and the fourth longitudinal position along the length of the balloon. 
     
     
         15 . The catheter system of  claim 14  wherein the system controller controls the energy source such that the plurality of pulses of energy from the energy source are sequentially directed to the first energy guide, then the second energy guide, then the third energy guide, and then the fourth energy guide so that the advancing wavefront is generated within the balloon interior that moves toward the treatment site in the first direction from near the balloon first end toward the balloon second end. 
     
     
         16 . The catheter system of  claim 14  wherein the plurality of energy guides further includes a fifth energy guide that is disposed along the catheter shaft and at least partially within the balloon interior, the fifth energy guide including a fifth guide distal end that is positioned within the balloon interior at a fifth longitudinal position along the length of the balloon that is different than the first longitudinal position, the second longitudinal position, the third longitudinal position and the fourth longitudinal position, the fourth longitudinal position being between the third longitudinal position and the fifth longitudinal position along the length of the balloon. 
     
     
         17 . The catheter system of  claim 16  wherein the system controller controls the energy source such that the plurality of pulses of energy from the energy source are sequentially directed to the first energy guide, then the second energy guide, then the third energy guide, then the fourth energy guide, and then the fifth energy guide so that the advancing wavefront is generated within the balloon interior that moves toward the treatment site in the first direction from near the balloon first end toward the balloon second end. 
     
     
         18 . The catheter system of  claim 16  wherein the system controller controls the energy source such that a first plurality of pulses of energy from the energy source are sequentially directed to the first energy guide, then the second energy guide, and then the third energy guide so that the advancing wavefront is generated within the balloon interior that moves toward the treatment site in the first direction from near the balloon first end toward the balloon second end; and wherein the system controller controls the energy source such that a second plurality of pulses of energy from the energy source are sequentially directed to the fifth energy guide, then the fourth energy guide, and then the third energy guide so that a second advancing wavefront is generated within the balloon interior that moves toward the treatment site in a second direction from near the balloon second end toward the balloon first end. 
     
     
         19 . The catheter system of  claim 1  wherein the advancing wavefront is spherical-shaped and impinges at an angle relative to the balloon wall to create a shearing force at the balloon wall substantially adjacent to the treatment site. 
     
     
         20 . The catheter system of  claim 1  wherein each of the plurality of energy guides includes an optical fiber; and wherein the energy source is a laser source that generates a plurality of pulses of laser energy.